A nationwide evaluation of antibiotics consumption in Swedish intensive care units

Background: Around 70% of all ICU patients are treated with antibiotics whereas up to 30% are suggested as unnecessary. Measuring antibiotic consumption is a prerequisite to improving its use and the purpose of the present investigation was to explore the use of antibiotics in Swedish ICUs. Material and methods: Daily Defined Doses (DDDs) of antimicrobials delivered to Swedish ICUs, 2016–2018, were retrieved from Swedish pharmacies. From the Swedish Intensive Care Registry, we extracted data on a number of patient admissions, occupied bed days and Simplified Acute Physiology Score (SAPS)3. Results: There was a similar annual rate of total DDDs per admission of 3.7, 3.5, 3.8 and total DDDs per 100 occupied bed days of 111, 111, and 115 but with an approximately 6-fold difference of DDDs per occupied bed days (61–366) between the ICUs. The most frequently used antibiotics were isoxazolyl penicillins (J01CF), penicillins with betalactamase-inhibitors, mainly piperacillin/tazobactam (J01CR), 3rd and 4th generation cephalosporins (J01DD + DE) and carbapenems (J01DH). Together these four classes accounted for a median of 52% of all antibiotic use. The use of carbapenems had a moderate positive correlation with the mean SAPS3 score (r = 0.6, p =.01). The use of other broad-spectrum antibiotics showed no such correlation. Conclusion: Overall antibiotic use remained similar in Swedish ICUs during the years 2016–2018. Broad-spectrum antibiotics accounted for 50% of all DDDs but with a large inter-ICU variation which only partly can be explained by differences in patient case mix and microbial resistance. Presumably, it also reflects varying local prescribing practices.